title: Establishment of norms of the beta angle to assess the sagittal discrepancy for Nellore district population.
abstract: OBJECTIVE
  In orthodontic diagnosis and treatment planning, assessment of anteroposterior discrepancy is of importance to the orthodontist. Both angular and linear measurements have been incorporated into various cephalometric analyses to help the clinician diagnose anteroposterior discrepancies and establish the most appropriate treatment plan. Hence the present study is designed to establish the norms of Beta angle to assess the sagittal discrepancy for Nellore district population.
  
  
  METHODS
  The sample was screened from the old records of the Orthodontic department of Narayana Dental College and Hospital. One hundred and fifty pretreatment cephalometric radiographs (50 each of Class I, II, and III) were subdivided based on ANB, Wits appraisal, and Beta angle into skeletal Class I, II, III. The same cephalograms were again classified into skeletal Class I, II, and III based purely on Beta angle. Each group was again divided into 2 subgroups consisting of 25 male and 25 female subjects with a mean age limit between 15 and 45 years old.
  
  
  RESULTS
  The Newman-keuls post hoc test and ANOVA showed that the 3 groups were significantly different (P ≤ 0.001). The Newman-keuls post hoc test also found the groups to be significantly different.
  
  
  CONCLUSIONS
  There was statistically significant difference for, the mean values and the standard deviation for Beta angle within the three skeletal patterns (Class I, Class II and Class III skeletal patterns). There was no statistically significant difference among the mean values of beta angle between Nellore district population and Caucasian norms and between male and female sex groups.
authors.affiliation: Department of Orthodontics and Dentofacial Orthopedics, Narayana Dental College and Hospital, Chinthareddypalem, Nellore, Andhra Pradesh, India.
authors.forename: Mandava
authors.initials: M
authors.lastname: Prasad
authors.forename: Karnati Praveen Kumar
authors.initials: KP
authors.lastname: Reddy
authors.forename: Ashok Kumar
authors.initials: AK
authors.lastname: Talapaneni
authors.forename: Nellore
authors.initials: N
authors.lastname: Chaitanya
authors.forename: Myla Vijay
authors.initials: MV
authors.lastname: Bhaskar Reddy
authors.forename: Rajendra
authors.initials: R
authors.lastname: Patil
keywords: Beta angle; cephalometrics; orthodontic diagnosis; sagittal discrepancy